nft: Fix a minor compilation warning

nft-shared.c: In function ‘nft_rule_to_iptables_command_state’:
nft-shared.c:454:22: warning: ‘jumpto’ may be used uninitialized in this function [-Wmaybe-uninitialized]
nft-shared.c:432:14: note: ‘jumpto’ was declared here

All verdicts are managed and jumpto has to get a value, but since
the compiler complains, let's fix it.

Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/iptables/nft-shared.c b/iptables/nft-shared.c
index cdc3f83..5681e26 100644
--- a/iptables/nft-shared.c
+++ b/iptables/nft-shared.c
@@ -429,7 +429,7 @@
 	int verdict = nft_rule_expr_get_u32(e, NFT_EXPR_IMM_VERDICT);
 	const char *chain = nft_rule_expr_get_str(e, NFT_EXPR_IMM_CHAIN);
 	struct nft_family_ops *ops;
-	const char *jumpto;
+	const char *jumpto = NULL;
 	bool nft_goto = false;
 
 	/* Standard target? */